High Resolution Orthoimagery, Polk and Beltrami Counties, MN, Spring 2014

This page last updated: 03/19/2015
Metadata created using Minnesota Geographic Metadata Guidelines

Go to Section:
1. Overview
2. Data Quality
3. Data Organization
4. Coordinate System
5. Attributes
6. Distribution - Get Data
7. Metadata Reference

Section 1 Overview
Originator Polk County; Beltrami County; Quantum Spatial, Inc.
Title High Resolution Orthoimagery, Polk and Beltrami Counties, MN, Spring 2014
Abstract This dataset contains leaf-off 4-band red, green, blue, infrared (RGBI) digital orthophoto imagery produced at 30-centimeter (approximately one-foot) resolution from new aerial photography captured in Spring 2014. The imagery covers Polk and Beltrami counties in northwestern Minnesota. This metadata record was created by the Minnesota Geospatial Information Office (MnGeo) using information supplied by Quantum Spatial Inc.
Purpose Support multi-agency efforts including transportation planning, wetland mapping, urban planning, forest management, soil mapping, and utility siting.
Time Period of Content Date 05/2014
Currentness Reference Ground condition. Imagery was flown May 16-23, 2014
Progress Complete
Maintenance and Update Frequency None Planned
Spatial Extent of Data Polk County and Beltrami County, Minnesota
Bounding Coordinates -97.20
Place Keywords Minnesota, MN, Polk, Beltrami
Theme Keywords imageryBaseMapsEarthCover, Orthophotography, Digital Orthophotography, Ortho, Orthophotos, Digital Orthorectified Images, Digital Orthophotos, DOQ, DOQQ, Imagery, Images, Aerial Photography, Aerial Photos, Digital Aerial Photography, Air Photo, Color Infrared, Four Band Imagery
Theme Keyword Thesaurus ISO 19115 Topic Category
Access Constraints Unrestricted
Use Constraints MnGeo Redistribution conditions: In obtaining this data from the Minnesota Geospatial Information Office (MnGeo), it is understood that you and/or your organization have the right to use it for any purpose. If you modify it, you are encouraged to apply responsible best practices by documenting those changes in a metadata record. If you transmit or provide the data to another user, it is your responsibility to provide appropriate content, limitation, warranty and liability information as you see fit.
Contact Person Information Steve Kloiber, Wetland Monitoring Coordinator
Minnesota Department of Natural Resources
500 Lafayette Road
St. Paul, MN  55155
Phone: 651-259-5164
Email: steve.kloiber@state.mn.us
Browse Graphic None available
Associated Data Sets For information on other air photos available for Minnesota, see: http://www.mngeo.state.mn.us/chouse/airphoto/

Section 2 Data Quality
Attribute Accuracy Radiometry is verified by visual inspection of the digital orthophoto. Slight systematic radiometric differences may exist between adjacent orthoimage files; these are due primarily to differences in source image capture dates and sun angles along flight lines. These differences can be observed in an image's general lightness or darkness when it is compared to adjacent orthoimage file coverages. Tonal balancing may be performed over a group of images during the mosaicking process which may serve to lighten or darken adjacent images for better color tone matching.
Logical Consistency None
Completeness All planned 2014 30-centimeter acquisition was completed. Orthoimages were visually inspected for completeness to ensure that no gaps or image misplacements exist within project limits and between adjacent images. These images were derived by mosaicking multiple images to ensure complete coverage. Source imagery was cloud free.
Horizontal Positional Accuracy Report from Quantum Spatial, Inc: 0.49 meters, CE 90. Horizontal accuracy was stated to meet or exceed 1.06 meters, CE90 or the 95% equivalent of 1.85 meters per NSSDA (National Standard for Spatial Data Accuracy). Airborne GPS data was collected during acquisition and ground control points surveyed. Some points were pulled out of the A/T and used as checkpoints to verify the DOQQ accuracy.

Report from the Minnesota Department of Transportation: Polk County imagery was collected as part of a larger project. MnDOT has enough test points to assess the accuracy of the entire project area but not enough for just the county. When available, the results of the larger project testing will be added to this metadata record.
Lineage Sources:
1. Minnesota 5-meter DEM, used to provide ground elevations for orthorectification process.
2. MN 30cm Area Aerotriangulation, Quantum Spatial, Inc., July 2014: Used to provide photo exterior orientations for orthorectification process.

Processing Steps:

The acquisition was done using multiple Intergraph DMCs (Digital Mapping Cameras) during 2014 Spring leaf-off conditions allowing for 5% snow and cloud cover. Digital camera(s) were calibrated by the manufacturer and the camera parameters refined through in-situ proprietary procedures. The flying height was 10,000-feet AMT (above mean terrain) and imagery data was captured in 12-bit for four bands (Red-Green-Blue-Near Infrared). The data was then processed using Intergraph's PPS software into 12-bit, 4-band images which were then adjusted using Intergraph's DIA (DMC Image Analyst) software.

The airborne GPS and IMU data was processed and used in beginning the aerial triangulation (AT) processing which was done using INPHO's Match-AT software. The resulting exterior orientations for each frame were used along with the DMC images and a 5 meter gridded DEM generated from the downloaded statewide LiDAR datasets to do a rectification using INPHO's OrthoMaster software. (Please note some DEM data into Canada and Wisconsin was downloaded from USGS NED DEM with minimal editing while the Dakota's data was downloaded LiDAR from the International Water Institute.)

The orthorectified frames were then further adjusted using INPHO's OrthoVista - Radiometrix Editor and seamlines automatically generated. Those seamlines were completely reviewed and edited to ensure no man-made features were clipped as well as to optimize seamline locations in general. Once the seamlines were edited the images were mosaicked and big tiles were cut for review and editing purposes.

The big tiles were completely reviewed and calls made for warped bridges and other artifacts which were then corrected. Then a QC was performed on 10-15% of the tiles focusing on urban areas and other important features. Once all QC edits were complete the big tiles were then used to cut out the final DOQQ tiles. Finally, the near-infrared band was adjusted per the client's direction and the images were formatted for final delivery.

Software versions: IRAS C ver 10.0, Photoshop ver CS5, Windows XP and Windows 7, INPHO OrthoVista 5.5, Global Mapper 13, Bentley MicroStation 7 and 8, INPHO Match-AT 5.5, INPHO OrthoMaster 5.5

Section 3 Spatial Data Organization (not used in this metadata)

Section 4 Coordinate System
Horizontal Coordinate Scheme Universal Transverse Mercator
UTM Zone Number 15
Horizontal Datum NAD83
Horizontal Units meters
Cell Width 0.3
Cell Height 0.3

Section 5 Attributes
Overview Imagery has 4 Bands with the order of Red, Green, Blue and Near Infrared.
Detailed Citation
Table Detail:

Section 6 Distribution
Publisher Minnesota Geospatial Information Office (MnGeo)
Publication Date 02/2015
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street, Room 300
St. Paul, MN  55155
Phone: 651-201-2489
Fax: 651-296-6398
Email: gisinfo.mngeo@state.mn.us
Distributor's Data Set Identifier SAIP Polk - Beltrami County
Distribution Liability MnGeo's full disclaimer is here: http://www.mngeo.state.mn.us/chouse/disclaimer.html
Ordering Instructions The imagery is available to view via WMS (Web Mapping Service) from MnGeo's Geospatial Image Server. The Minnesota Geospatial Image Service web pages provide the url to connect to the Geospatial Image Server as well as information about how to use WMS services. Due to file size there is currently no option to download the photos.

Access via the Minnesota Geospatial Commons by clicking on the 'Online Linkage" field below.
Online Linkage I AGREE to the notice in "Distribution Liability" above. Clicking to agree will either begin the download process, link to a service, or provide more instructions. See "Ordering Instructions" above for details.

Section 7 Metadata Reference
Metadata Date 03/19/2015
Contact Person Information Nancy Rader, GIS Data Coordinator
Minnesota Geospatial Information Office (MnGeo)
658 Cedar Street, Room 300
St. Paul, MN  55155
Phone: 651-201-2489
Fax: 651-296-6398
Email: gisinfo.mngeo@state.mn.us
Metadata Standard Name Minnesota Geographic Metadata Guidelines
Metadata Standard Version 1.2
Metadata Standard Online Linkage http://www.mngeo.state.mn.us/committee/standards/mgmg/metadata.htm

This page last updated: 03/19/2015
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